.75 cal smoothbore pistol

I'm having a .75 cal pistol made.Does any one know what size powder charges I should start with.Is 50-55 grains to much. the barrel is 12 in. and 1 1/8

No matter how you look at it, the bullet ( ball) drop on this size of ball is going to be great, unless you get it up to 3000 fps.
That won't happen.
So 40-60 grains is lots.
It will still be only a 40 yard gun, with minimal potential as a target gun.
Best regards
Old Ford

I had a pair of smoothbore pistols. One was .62 and the other was .64. 35 grains of 3F was plenty of powder for those. I agree with Ford, I wouldn't go much over 40 grains. Remember you don't have a shoulder to take up the recoil and smoothbore pistols are relatively light weight.

Maximum effective range is about 15 to 20 yards. Buck and ball or buckshot only increases the chances of hits.

Many Klatch

Ok when I said 50-55 grs.I was talking about FF powder.how much if a difference is there between 2F and 3F,and can I use 2F in it.I use 1F in my rifle.

2F will work fine. I just had 3F on hand and used it. I don't know that I would use 1F in a rifle unless it had a 1" bore.

I like to use 3F in my .60 smoothbores because it shoots cleaner. I use 2F in my Bess. 90 grains of 2F will rock me back when pushing a 550 grain .715 roundball.

I think 55 grains of 2F in a .75 pistol is going to be real rough on your wrist. I shoot 35 grains of 3F in my .44 flint pistol and .44 Remington.

Many Klatch

sorry the pistol is rifled not a smoothbore.the barrel size is 1 and 1/8 inches .75 caliber. I have a matching rifle that has a 1 and 1/4 inch barrel and weighs 14 pounds.It likes 125 gr. of 2F or 135gr.of 1F. the pistol will shoot the same ball and patch as the rifle .735 ball .018 pillow ticking average ball weight 590 gr.

stalkerhawk said:

I'm having a .75 cal pistol made.Does any one know what size powder charges I should start with.

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I wonder if the builder would have a recommendation?

I'm going to ask,but I wanted to see if I could get broader opinion :hmm: :hatsoff:

I'd say to start lower and work your way up to where it either gets accurate or hurts too much. :haha:

Be sure and let us know what you find out. Sounds like fun.

stalkerhawk said:

I'm having a .75 cal pistol made.Does any one know what size powder charges I should start with.Is 50-55 grains to much. the barrel is 12 in. and 1 1/8

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There is a reason why there are not a lot of original pistols in this bore size. Shooting a 600+ grain ball from a pistol is going to be pretty nasty even at 400-500 FPS.

Dan

Here is a replica of unknown origin and without any proof stamp ; the barrel is thin and so loads are reasonable :



load : 40grs BP, 100grs cornmeal and patched 75 ball. Cornmeal is essential for regularity.......

All balls within target at 25meters (when everything goes right): not so bad !!!!!!!!!!!!

A .750 caliber (.75 inch) rifled bore with a 1.125 inch outer measurement sounds like a rather thin wall, not horribly thin just thinner than most flintlock pistols, so my inclination would be to not load it up too stoutly.

I have on occasion shot 50-55 grains of 3F in a 58 caliber pistol Harper's Ferry Flintlock. Over 12 inch heavy barrel, much heavier than that 75 cal barrel you posted about. The recoil was stout for sure, but manageable! I normally shoot 40 grains of 3F under a .530 patched round ball for just playing around poking holes in cardboard "pirates". I would use 50 grains for hunting or for self-protection or any actual use other than poking holes in targets.

With a significantly heavier lead ball (.735-ish to .530 in diameter) you will get MORE felt recoil than I would with the same grain weight of powder. My lead ball weighs ion about 225 grains and yours weighs 590 grains... that is a lot of difference in payload and you will feel that the more you load up the black powder.

So, I would say 40 grains of 3F is plenty for your rather thin walled 75 caliber pistol.

The 2F might be just slightly less recoil at the exact same grain weight of powder.

I meant to type .570 diameter lead ball in that 58 caliber pistol which would be about 280 grains of weight of the ball compared to your 590 grains of weight..... still big difference.

.75 is basically an 11 gauge.

Yea I would think 40 grains of black powder would be more than enough under all that payload if you want to be able to use that hand you shoot that thing off with.

sounds good.thanks guys.looks like I'll start at 35 gr.and work up to 45 gr. recoil doesn't worry me SAFETY does.I shoot a 5 shot .45/70 revolver.
the bullet is 405.0 grs.Its got some kick,but I don't have a problem with it. Even shooting single handed.

Is that a smooth bore,and would I still need to use cornmeal in a rifled barrel?

Hi,
Your cartridge revolver will not break at the pistol grip, like many BP pistols ( see Lyman pistols ).
Unless your stock is carefully selected, like flowing grain ( bent branch ?? ) into the grip.
Breakage is often a possibility.
A laminated stock will also prevent breakage as
well.
All the best.
Merry Christmas!
Old Ford

stalkerhawk said:

sounds good.thanks guys.looks like I'll start at 35 gr.and work up to 45 gr. recoil doesn't worry me SAFETY does.I shoot a 5 shot .45/70 revolver.
the bullet is 405.0 grs.Its got some kick,but I don't have a problem with it. Even shooting single handed.

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So what does the 45-70 weigh vs the 75 caliber ML pistol? The 45-70 probably weighs as much as some modern lightweight rifles do. 5 pounds +.
Having shot a 45-70 revolver for a photo for a gunwriter friend I can attest that the recoil is actually pretty mild with the 405 gr factory load.
The revolver MOVES a lot. But its not violent.
A short barreled airweight S&W 38 Special with 158 gr RN is worse from the pain index standpoint.


Dan

I really do not think this original poster is talking about a revolver!

He is talking about a flintlock, I think.

75 Caliber. smoothbore as the title says.

Oldford thank's I didn't know that.Dan I don't know the weight of the .75 it hasn't been built yet.The revolver weighs 4 lbs. I'm not sure I would call the recoil mild...most people who see it, or hear 45/70 GOV'T think fly out of your hand recoil.I have two rifles people warned me not to get due to recoil.Turns out I love them,and shoot them the most.The post states smoothbore,but I changed my mind and the pistol will now be rifled.